Rotary switch with improved contact positioning



ROTARY SWITCH WITH IMPROVED CONTACT POSITIONING Filed March 29, 1965 y 1957 A. E- GRATRIX, SR

5 Sheets-Sheet 1 y 4, 1967 A. E. GRATRIX, SR 3,329,780

ROTARY SWITCH WITH IMPROVED CONTACT POSITIONING Filed March 29, 1965 3 Sheets-Sheet 2 INvzN'roR ALFRED E. Gem-magsa July 4, 1967- 3,329,780

ROTARY SWITCH WITH IMPROVED CONTACT POSITIONING Filed March 29, 1965 A. E. GRATRIX, SR

5 Sheets$heet 5 INVENTOR ALFRED E,GRATRIX,SE

United States Patent F 3,329,780 ROTARY SWITCH WITH IMPROVED CONTACT POSITIONING I .Alfred E. Gratrix, Sr., Trumbull, Conn., assignor to Gen- The present invention relates to a rotary switch and, more specifically, to a switch which is operated by a rotatable cam so that the switch is closed at a preselected position during each revolution of the cam.

A primary object of the present invention is to provide a new and improved rotary switch. Another object is to provide a new and improved switch, the operation of which is control-led by a rotatable cam, so that the switch is closed at a preselected position during each revolution of the cam. A related object is to provide such a rotary switch wherein the position during each cam revolution at which the switch is closed is adjustable. Still another object of the present invention is to provide a new and improved rotary switch which includes a plurality of pairs of switch contacts and which is operated by a rotatable cam so that the pairs of contacts are closed at diiferent preselected times during each revolution of the cam.

A more specific object of the present invention is to provide a new and improved rotary switch which is closed at a precise, preselected time during each day, i.e., during each twenty-four hour period.

Another more specific object of the present invention is to provide a new and improved rotary switch including a rotatable cam member having a camming surface thereon and including at least one pair of contacts having a cam follower associated therewith which engages the cam member so that the switch is closed during each revolution of the cam member when the follower engages the camming surface. A related object is to provide such a switch characterized in that the contacts may be rotated relative to the cam member so that the position during each revolution of the cam member at which the follower is adjacent the detent may be varied.

A general object of the present invention is to provide a new and improved rotary switch characterized in its sturdiness, lightweight, economy, compactness and reliability.

Other objects and advantages of the invention will become apparent upon reading the attached detailed description and upon reference to the drawings, in which:

FIGURE 1 is a perspective view of a first exemplary rotary switch embodying the present invention;

FIG. 2A is an end View of the switch in FIG. 1 showing the switch in the open position;

FIG. 2B is an end view corresponding to FIGS. ZA showing the switch in the closed position;

FIG. 2Cis an end view corresponding to FIG. 2A showing the switch in the locked-open position;

FIG. 3 is a perspective view of a second exemplary rotary switch embodying the present invention;

FIG. 4 is a front cross sectional view of a duplex rotary switch assembly utilizing switches as shown in FIGS. 1 and 3;

FIG. 5 is a perspective view of a third exemplary rotary switch embodying the present invention;

FIG. 6 is an end view of the switch in FIG. 5 showing the switch in the closed position;

FIG. 6A is a fragmentary section showing the switch blades in profile;

FIG. 7 is a cross sectional view of FIG. 6 taken along lines 7--7; and

FIG. 7A is a fragmentary section taken along the line 7A7A in FIG. 7.

3,329,780 Patented July 4, 1967 While the invention has been described in connection with certain preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, the invention is intended to cover the various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

In accordance with the present invention, a newand improved cam operated rotary switch is provided wherein the switch is closed at a preselected position or time during each revolution of the cam. More specifically, such a rotary switch is provided which includes at least one pair of contacts having a cam follower connected thereto that is associated with the cam for cooperating with means on the cam so that the contacts are closed when adjacent the means, the pairs of contacts being rotatable relative to the cam so that the position at which the contacts are closed is adjustable. Referring to FIGS. 1-3, a first exemplary rotary switch embodying the present invention is illustrated. In the exemplary arrangement, the rotary switch is associated with a main housing or panel 21.

The rotary switch includes a cylindrical cam member 11 which has a V-shaped notch or detent 11a formed therein and which is mounted on a shaft 12 for rotation therewith. The shaft 12 is driven by a motor 13 through a gear 14, the motor, for example, operating at a speed of one-half revolution per hour and the gear 14, for example, having a 12:1 reduction ratio so that the shaft 12 and the cam member 11 are rotated at a speed of one revolution per twenty-four hours. It will be appreciated, however, that the shaft 12 may be driven by any suitable means and at any suitable speed.

A contact assembly 15 is provided for the purpose of producing a switching operation and, as may be seen, includes a pair of contact members 15a and 15b which maybe respectively connected to a desired circuit by means of terminals 16a and 1611 so that operation of the circuit is controlled thereby. In the exemplary arrangement, the contact members 15a and 15b ars assumed to be spring biased toward one another so that, in the absence of external opposing force, the contact members are in engagement, i.e., the switch is closed. The contact assembly is secured to a set wheel in the form of a cup-like housing 18 for rotational movement therewith. The contacts are secured to an insulating boss 17 which, in turn, is fixed to the inner surface of the wheel 18. The cup-like wheel 18 has a centrally located circular aperture 18a for receiving the shaft 12, the aperture 18a having a larger diameter than the shaft 12 so that the wheel 18 may be rotated relative to the shaft and thus relative to the cam member 11. For the purpose of locking the cup- 'like wheel 18 in a desired position, a plurality of detents are provided around the inner surface of the outer wall thereof which are engaged by a detent spring 20, the detent spring 20* being secured to a plate 20:: which is secured to the main housing or panel 21. The detent spring 20 is assumed to be resilient so that the cup-like wheel 18 may be manually rotated with respect thereto.

For the purpose of causing the contact members 15a and 15b to be moved into and out of engagement with one another, i.e., for the purpose of controlling the opening and closing of the switch, a V-shaped cam follower 22 is. formed integrally with the upper contact members 15a. As may be seen, the contact assembly 15 is positioned so that the outer surface of the cam member 11 is engaged by the cam follower 22. When the cam follower 22 is in engagement with the nondetented portion of the cam member 11 (FIG. 2A), the spring biasing of the contact members 15a and 15b is opposed and the contact members are maintained in their open or nonengaging positions. Conversely, when the detent 11a of the cam member 11 is adjacent the cam follower 22 (FIG. 2B),

the cam follower is driven into the detent by the spring biasing force of the cotnact member a so that the contact members are moved into engagement, i.e., are closed.

In view of the foregoing, it follows that, if the cup-like wheel 18 is rotated until the contact assembly 15 is in a desired relative position in respect of the cam member 11, the switch will be closed, i.e., the contact members 15a and 15b will be moved into engagement, when the detent 11a reaches a desired angular position during each revolution of the cam member 11. Thus, the switch may be preset to be closed at a precise, preselected position or time during each revolution of the cam member 11.

For the purpose of locking the contact members 15a and 15b in the open or nonengaged position, a latching member is provided which is pivotable about a shaft 26. The pivoting movement of the latching member 25 is limited to a prescribed are by opposite ends thereof 25a and 25b engaging the main housing or panel 21. As may be seen, the latching member 25 has a lip or flange 27 which can slip under a lip or flange 28 on the cam follower 22 when the cam 11 is positioned to hold the contact assembly 15 in its open position as shown in FIG. 1, and then holds the contact assembly 15 open afterwards even when the cam detent 1111 later passes under the follower 22 as in FIG. 2C. Starting with the cam 11 and the assembly of the wheel 18 and contacts 15 in the positions of FIG. 2A, the wheel 18 is rotated clockwise. This moves the pin 30 out from under the latch member 25, allowing the latch member to drop gravitationally to the position of FIG. 1, which is the counterclockwise limit of its rotation. As the cup-like wheel 18 is rotated further in the clockwise direction, a point will be reached whereat the rear surface 31 of the latching member 25 is engaged by the pin 30 on the wheel 18. Then since the latching member 25 is pivoted to its limit in the counterclockwise direction about the shaft 26 (i.e., the main housing or panel 21 is engaged by the end 25a of the latching member), further clockwise rotational movement of the wheel 18 is prevented by the latching member 25. The contact assembly 15 also moves with the wheel 18, and the lip or flange 28 of the cam follower 22 is adjacent the pin 30 so that the lip or flange 28 is engaged by the lip or flange 27 of the latching member 25, as shown in FIG. 2C, and the contact members 15a and 15!) are then maintained in the open or nonengaging position even when the detent 11a is adjacent the cam follower 22. To disengage the flanges 27 and 28, the wheel 18 is simply moved counterclockwise to retract the contact assembly 15.

In view of the foregoing, it will be apparent that the pin 30 and the latching member 25 cooperate to limit the clockwise rotational movement of the cup-like wheel 18, as viewed in FIGS. 2A-2C, further movement being prevented when the end 25a of the latching member 25 engages the main housing 21. Additionally, the pin 30 and the latching member 25 cooperate to limit the counterclockwise movement of Wheel 18, as viewed in FIGS. 2A- 2C. When the housing 18 is rotated counterclockwise, a point is reached whereat the pin 30 engages the forward surface 32 of the latching member 25. As further counterclockwise movement is imparted to the housing 18, the latching member 25 is pivoted in the clockwise direction about the shaft 26 until the main housing 21 is engaged by the end 25b of the latching member (FIGS. 2A and 2B). Further counterclockwise movement of the wheel 18 is then prevented by the latching member 25. The width of the lower end of the member 25 where it engages the pin 30, and the length of the allowed arcuate travel of member 25 are so selected that the pin 30 and the latching member 25 cooperate to allow the wheel 18 to rotate a full 360 degrees, but no more than that, so that the leads connected to the switch assembly 15 are not cumulatively wrapped around the shaft 12.

If it is assumed that the cam member 11 is driven at a rate of one revolution per twenty-four hours and if it is further assumed that ninety-six equally spaced detents are provided for cooperating with the resilient detent spring 20, it follows that the contact assembly 15 may be prepositioned at ninety-six different angular positions relative to the cam member 11. Since the cam member is rotated one revolution per twenty-four hours, it follows that the switch may be preset to close at any desired one of ninetyfive quarter-hour time intervals during the period from 12:00 midnight to 11:45 pm. during each daily revolu tion of the cam member. The ninety-sixth position is off," i.e., the locked-open position of the contacts 15 described above. Under these conditions, a rotary switch has been provided which is closed at a desired, preselected time during each day. For the purpose of providing an indication of the preset time at which the switch will close, time markings corresponding to ninety-five of the ninety-six different quarter-hours during a day plus a marking corresponding to the off position may be provided on the outer surface of the cup-like wheel 18, as shown in FIG. 1, the markings corresponding to the ninety-six detents for the detent spring 20. As may be seen, a slot 35 is provided in an escutcheon plate 10 so that the time markings on the cup-like wheel 18 may be viewed therethrough. Additionally, an indicating point 36 provided on the escutcheon plate 18 to indicate the preset time.

Referring to FIG. 3, a second exemplary rotary switch embodying the present invention is illustrated which is similar to the switch shown in FIG. 1 and which is likewise associated with a main housing or panel 121. The second embodiment differs from the first in that an outwardly projecting boss or protuberance 111a is formed on the outer surface of a cylindrical cam member 111 rather than a detent being formed therein. The carn member is mounted on a shaft 112 which may correspondingly be driven by a motor 113 through a gear arrangement 114.

For the purpose of producing a switching operation, a contact assembly 115 is provided which includes a pair of contact members 115a and 115b, the contact members being respectively connected to a desired circuit by means of terminals 116a and 11612 for controlling the operation of the circuit. In the exemplary arrangement, the contact member 115a is assumed to be rigid, whereas the contact member 1115b is assumed to be flexible. Additionally, it is assumed that, in theabsence of external force, the contact members are not in engagement, i.e., the switch is open. By means of the insulating boss 117, the contact assembly 115 is secured to a cup-like set wheel 118, corresponding to the wheel 18 of FIG. 1, for rotational movement therewith. Accordingly, the cup-like wheel 118 has a centrally located circular aperture 118a for receiving the shaft 112 and the aperture 118a has a larger diameter than the shaft 112 so that the housing 118 may be rotated relative to the shaft and, thus, relative to the cam member 111. For the purpose of locating the cup-like wheel 118 in a desired position, a plurality of detents are provided around the inner surface of the outer wall thereof which are engaged by a resilient detent spring 120, the detent spring 120 being secured to a plate 121 which may, in turn, be secured to the main housing or panel 121.

For the purpose of causing the contact members 115a and 11512 to be moved into and out of engagement with one another, i.e., for the purpose of causing the switch to be opened and closed, a U-shaped cam follower 122 is formed integrally with the lower contact member 115b. As may be seen, the contact assembly 115 is mounted on the cup-1ike wheel 118 so that the cam follower 122 is engaged by the boss 111a when the cam member 111 is rotated. When the boss engages the cam follower 122, the lower contact member 115b is driven into engagement with the upper contact member 115a so that the switch is thereby closed.

In view of the foregoing, it follows that, if the cup-like wheel 118 in the switch of FIG. 3, like the cup-like wheel 18 of the switch in FIG. 1, is rotated until the contact assembly 115 is in a desired relative position in respect of the cam member 111, the switch will be closed when the boss 111a reaches a desired angular position during each revolution of the cam member 111. Thus, the switch may be preset to be closed at a precise, preselected position or time during each revolution of the cam member 111. This embodiment has a full ninety-six switch-operating positions and no off position.

For the purpose of limiting the rotational movement of the wheel 118, a pin 130 is slidably mounted in an armate slot 131 of the wheel 118. As the wheel 118 is rotated in the clockwise or counterclockwise direction, it will be apparent that a position is reached whereat the pin 130 engages an extending arm 121a of the plate 121 so that further rotational movement of the wheel 118 is prevented. The slot 131 is provided to allow some arcuate movement of the pin 130 whereby the wheel 118 is permitted to be rotated through a full 360 degrees, but no more, since in the exemplary arrangements, it is desirable to limit the amount of rotational movement of the wheels 18 and 118 to 360 degrees to prevent the associated leads connected to the terminals 16a and 16b and 116a and 11617 from being cumulatively wrapped around the shafts 12 and 112.

The rotary switch in FIG. 3 also is provided with a slot 135 in an escutcheon plate 110 so that time markings on the cup-like wheel 118 may be viewed therethrough. Additionally an indicating point 136 is provided on the escutcheon plate 110 to indicate the preset time.

If a pair of cup-like Wheels 218 and 218, corresponding to either of those previously described (FIGS. 1 or 3), are provided, as shown in FIG. 4, and if an individual contact assembly 215 and 215' is associated with each housing, it will be apparent that a rotary switch is provided which may be preset so that the two pairs of contact members close at different, preselected times during each revolution of the cam member 211. Thus, it follows that a pair of operations may be controlled by a single switch assembly. Finally, it will be apparent that a plurality of rotary switches, as described hereinabove, may be mounted on the same shaft for controlling a plurality of different operations.

A further embodiment of the invention including a number of additional features of novelty is set forth in FIGS. 5-7A inclusive. In this embodiment the driven member or cam 211 is in the form of a tubular shaft having a cam groove 211a extending axially along one side. The member 211 extends through, and is supported by, a pair of spaced frame plates 221. For driving the member 211 slowly upon passage of time it is connected to a drive shaft 212 powered by a synchronous or other time-regulated driving motor 213 and with an interposed gear reducer 214. Thus, in a practical case, the motor 213 may have an output speed of one-half revolution per hour and the reducer may provide a reduction in the ratio of 12:1 so that the cam member 211 rotates on a 24-hour cycle.

For the purpose of making an electrical contact when the member 211 reaches a predetermined phase position, a contact assembly 215 is provided consisting of a pair of leaf spring contacts 215a, 21512. In accordance with the invention, the contact assembly 215 is mounted within a hollow 217 formed in an annular setting wheel 218 which is preferably made of molded plastic. The inner diameter of the wheel 218 is preferably such as to provide sliding clearance with respect to the rotating member 211 with sufficient area and contact so that the wheel is stably supported without obvious looseness or play.

To bring out electrical connections contact rings are provided on the opposite sides of the wheel 218, seated in suitable annular recesses, with the contact rings being engaged by a pair of fixed contact spring members and with the rings being corrugated to provide a large number of closely spaced detent positions. Thus, I provide a first ring 21% and a second ring 2180 on opposite sides of the wheel 218 and facing in opposite directions. The rings are preferably pressed into corrugated shape from a flat ring- 6 shaped blank (see FIG. 7A) and may be secured in seated position, in their respective grooves, by cementing.

For the purpose of engaging the contact rings, a fixed contact assembly 220 is provided formed of an insulating support, or body, 220a carrying downwardly projecting contact spring 220b, 220a. Connections to these springs may be brought out to terminals 216a, 216b. The spring contacts are preferably in the form of lengths of wire having good conducting characteristics as well as a high degree of resilience, with the lower or free ends thereof bent inwardly around the rim portion of the wheel. Since the wheel 218 is free to move endwise, it assumes a position of equilibrium between the two spring members 220b and 2200 so that the forces applied by these members are equalized. Indeed, since the forces exerted by the contact springs upon thet wheel 218 are directly opposed, in addition to being equal, the two forces are self-canceling. Thus, while the springs provide good electrical contact and positive detenting action, the wheel 218 is free to float both radially and endwise imposing minimum frictional loading upon the central member 211.

With the above organization in mind, more detailed attention may be given to the nature and mounting of the electrical contact members 215a, 2151b. These contact members are preferably provided with mounting pads 2150, 215d shown in FIG. 6A, secured to sidewalls on the Wheel 218 which define the recess 217. Contact strips are provided for connecting the pa d 2150 of the contact 215a with the contact ring 218b, for example as shown at 218d in FIG. 7. A similar connection is made between the pad 215d of contact 21512 and the contact ring 2180.

For the purpose of responding to the arrival of the groove 211a on the cam member 211, the contact blade 21511 has a relatively sharp bend or offset 222 which serves as a cam follower. Under normal circumstances the portion 222 of the contact blade rides idly on the surface of the member 211 but upon passage of time the groove is rotated into a condition of register permitting the contact blade to drop into the groove so that electrical contact is established with the opposing contact 21511. For the purpose of supporting the contact 2151) in a predetermined position, the tip of the latter is bent to provide a smooth offset portion 233 which serves as a shoe riding constantly on the surface of the member 211.

To facilitate setting the wheel 218 in a desired phase position, a time scale 218a is provided about the periphery divided into quarter hour intervals. Correspondingly, the contact rings 218b, 218a may provide a total of ninetysix detent positions. The time scale is viewable through an escutcheon plate 210 having a rectangular opening 235 and carrying an index mark 236.

When it is desired to set the wheel 218 to produce contact at a predetermined time, the wheel 218 is turned, by fingertip pressure, in either direction until the time appears opposite the index on the escutcheon. The operator has complete freedom to move the wheel in either direction without striking any bottoming stops. Thus, it is always possible to move the wheel in a direction which will produce the desired setting with the least amount of movement; for example, it is possible to move the wheel from the 2300 posiiton to the 0100 position directly and without striking a stop at the 2400 position. Consequently, the limitations normally associated with wire leads are eliminated and reliability is substatnially increased since there is no possibility of breaking the connection by reason of repeated flexure. It is apparent, therefore, that the construction shown in FIG. 5 offers a number of practical advantages over the earlier-described embodiments of the invention.

While the invention has been. discussed in connection with a single wheel 218, it is one of the features of the invention that a large number of such wheels may be mounted side by side, limited only by the axial space available on the member 211. A separate stationary contact assembly 220 is provided for each of the wheels to be accomodated, and the additional contact assemblies are simply arranged side by side, for example, on a cross memher or rail 221a forming a portion of the supporting frame. As stated, each contact assembly, applying balanced forces to the wheel which it engages, serves to define the axial position of its wheel along the member 211.

It is one of the inherent features of the construction that positive detenting may be secured insuring operation of the contacts at a predetermined time while still enabling the wheel to be turned with light fingertip pressure. The reason for this is that detenting occurs at a radius which is greater than the radius of the contact cam follower. This tends to minimize the tendency for a setting ring to be pulled out of position after contact is made and upon continued rotation of the central driving member. A further feature which is inherent in the construction described above relates to the removability of the setting rings 218 when desired for replacement or for cleaning or inspection of the contacts. To release the setting rings 218, the central carn member 211 is simply drawn endwise from the frame permitting the rings to be drawn through the lower frame opening with automatic disconnect at the stationary contact assemblies. For reinstallation, the wheels are simply inserted from below until the contact springs 2201), 220a snap over the rims of the respective wheels into seated position on the contact rings, whereupon the central drive or cam member 211 may be reinserted.

I claim as my invention:

1. In a rotary switch, the combination which comprises, a rotatable, cylindrical cam member having an axial camming means on the periphery thereof, a cup-like set Wheel positioned adjacent the cam member with the cam member disposed therein, a pair of contacts having a first position and a second position mounted on the set wheel adjacent the periphery of the cam member, a cam follower connected to said set wheel and positioned in engagement with the periphery of said cam member and for moving said contacts from said first position to said second position when said cam follower engages said camming means, the set wheel being rotatable relative to the cam member to position the cam follower relative to the cam member so that the position during each revolution of the cam member at which the cam follower engages the camming means may be varied, and latching means connected to said switch and operable to maintain said contacts in the first position when brought into engagement with at least one of said contacts, the latching means also limiting the clockwise and counterclockwise rotational movement of said set wheel while allowing for adjustment thereof through 360 degrees.

2. In a rotary switch, the combination which comprises, a rotatable, cylindrical cam member having an axial camming means on the periphery thereof, a cup-like set wheel positioned adjacent the cam member in surrounding relationship, said set wheel having an outer wall with a plurality of detents formed on the inner surface of said wall, a pair of contacts. having a first position and a second position mounted on the set wheel adjacent the periphery of the cam member, said contacts normally being in said first position, a cam follower connected to said switch and positioned in engagement with the periphery of the cam member and for moving said contacts to said second position only when the camming means is engaged by the cam follower, the set wheel being rotatable relative to the cam member to position the cam follower relative to the cam member so that the position during each revolution of the cam member at which the cam follower engages the camming means may be varied, said set wheel further having a pin member axially secured thereto, a pivotable latching member connected to said switch, the latching member being engaged by the pin member and by one of said contacts to thereby lock said contacts in said first position when the set wheel is rotated in a first direction to limit rotational movement, the latching member being engaged by the pin member when the set wheel is rotated in the opposite direction to limit rotational movement, the latching member and the pin member limiting the clockwise and counterclockwise rotational movement'of the set wheel while allowing for adjustment thereof through 360 degrees, and means including a resilient detent spring member in engagement with the plurality of detents to releasably hold the set wheel in a desired rela tive position.

3. In a rotary switch, the combination which comprises, a rotatable, cylindrical cam member having at least one axial camming means on the periphery thereof, a set wheel positioned adjacent the cam member in surrounding relationship, a pair of contacts having a first position and a second position mounted on the set wheel adjacent the periphery of the cam member, cam follower means connected to said switch and positioned for engaging the cam member and for moving said contacts from said first position to said second position when a camming means is engaged by said cam follower means, the set wheel being rotatable relative to the cam member to position said cam follower means relative to the cam member so that the position during each revolution of the cam member at which the cam follower means engages a selected camming means may be varied, and latching means connected to said switch for engaging said contacts at a desired point in the rotation of said set Wheel to lock said contacts in said first position.

4. In a rotary switch, the combination which comp-rises, a rotatable, cylindrical cam member having an axial camming means on the periphery thereof, a cup-like set wheel positioned adjacent the cam member so that the cam member is disposed therein, a pair of contacts having a first position and a second position mounted on the set wheel adjacent the periphery of the cam member, a cam follower connected to said set wheel and positioned in engagement with the periphery of said cam member and for moving said contacts from said first position to said second position When said cam follower engages said camming means, the set wheel being rotatable relative to the cam member to position the cam follower relative to the cam member so that the position during each revolution of the cam member at which the cam follower engages the camming means may be varied, and means connected to said switch for limiting the clockwise and counterclockwise rotational movement of the contacts and cam follower While allowing for adjustment thereof through 360 degrees.

5. In a rotary switch, the combination which comprises, a rotatable, cylindrical cam member having an axial camming means on the periphery thereof, a cuplike set wheel positioned adjacent the cam member in surrounding relationship and having an arcuate slot formed therein, said set wheel also having an outer wall with a plurality of detents formed in the inner surface of said wall, a pair of contacts having a first position and a second position mounted on the set wheel adjacent the periphery of the cam member, a cam follower connected to said set wheel and positioned in engagement with the periphery of said cam member and for moving said contacts from said first position to said second position when said cam follower engages said camming means, the set wheel being rotatable relative to the cam member to position the cam follower relative to the cam member so that the position during each revolution of the cam member at which the cam follower engages the camming means may be varied, means connected to said switch including a resilient detent spring member which engages the plurality of detents to releasably hold the set wheel in a desired relative position, a pin slidably mounted in the arcuate slot and connected to said switch, a fixed stop in the path of movement of the pin for limiting the clock wise and counterclockwise rotational movement of the contacts and cam follower while allowing for adjustment thereof through 360 degrees.

6. In a rotary switch, the combination which comprises, a rotatable, cylindrical cam member having an axial camming means on the periphery thereof, a nannular set wheel positioned adjacent the cam member in surrounding relationship, a pair of contacts having a first position and a second position mounted on the set wheel adjacent the periphery of the cam member, a cam follower connected to said set wheel and positioned in engagement with the periphery of said cam member and for moving said contacts from said first position to said second position when said camming means engages said cam follower, the set wheel being rotatable relative to the cam member to position the cam follower relative to the cam member so that the position during each revolution of the cam member at which the cam follower engages the camming means may be varied, and means including electrical wiper contacts for releasably holding the set wheel in a desired relative position.

7. In a rotary switch, the combination which comprises, a rotatable, cylindrical cam member having an axial camming means formed in the periphery thereof, an annular set wheel positioned adjacent the cam member in surrounding relationship and having a plurality of conductive detents formed in opposite sides thereof, a pair of contacts having a first position and a second position mounted on the set wheel adjacent the periphery of the cam member, the contacts being respectively connected electrically to the detents on opposite sides of the set wheel, a cam follower connected to said set wheel and positioned in engagement with the periphery of said cam member and for moving said contacts from said first position to said second position when camming means engages said cam follower, the set wheel being rotatable relative to the cam member to position the cam follower relative to the cam member so that the. position during each revolution of the cam member at which the cam follower engages the camming means may be varied, and means including a pair of electrical wiper contacts e11- gaging the detents to releasably hold the set wheel in a desired relative position and to provide electrical contact with the contacts.

8. In a rotary switch, the combination comprising, a single, substantially cylindrical shaped rotatable cam member having an axial camming means on the periphery thereof, a plurality of substantially annularly shaped set wheels supported by said cam member in surrounding relationship with said cam member, each of said set wheels having a pair of contacts mounted thereon and a cam follower connected thereto, the cam follower connected to each of said set wheels being so positioned that it engages the periphery of said cam member and moves the contacts on said set wheel from a first position to a second position upon engaging said camming means, and each of said set Wheels being independently rotatable relative to said cam member whereby the position during each revolution of the cam member at which the camming means engages the cam follower connected to any one of said set wheels may be independently varied.

9. In a rotary switch, the combination comprising, a rotatable cam member having an axial camming means on the periphery thereof, a plurality of cup-shaped set wheels positioned adjacent the cam member in surrounding relationship, each of said set wheels having a pair of contacts mounted thereon, a cam follower connected thereto, and an outer wall with a plurality of detents formed in the inner surface of said wall, the cam follower connected to each of said set wheels being so positioned that it engages the periphery of said cam member and moves the contact of said set Wheel from the first position to a second position upon engaging said camming means, each of said set wheels being independently rotatable relative to said cam member whereby the position during each revolution of the cam member at which the cam follower connected to any one of said set wheels engages the camming means may be independently varied, and respective detent springs engaging the detents on the respective set wheels whereby each of said set wheels is releasably held in a desired relative position.

10. In a rotary switch, the combination comprising, a rotatable cam member having an axial camming means on the periphery thereof, a plurality of annular set wheels positioned adjacent said cam member in surrounding relationship; each of said set wheels having a pair of contacts mounted thereon, a cam follower connected thereto, respective conductive rings formed of a plurality of detents on opposed sides thereof, and electrical conducting means connecting each of said contacts to a respective one of said rings, a respective electrical wiper contact engaging each of said rings, a cam follower connected to each of said set wheels and so positioned that it engages the periphery of said cam member and moves the contacts on said set wheel from a first position to a second position upon engaging said camming means, each of said set wheels being independently rotatable relative to said cam member whereby the position during each revolution of the cam member at which the cam follower connected to any one of the set wheels engages the camming means may be independently varied, and each of said set wheels being releasably held in a desired relative position by the wiper contacts engaging the rings on the opposed sides thereof.

11. In a rotary switch, the combination comprising, a rotatable cam member having axially extending camming means on the periphery thereof, a set wheel positioned adjacent the cam member in surrounding relationship, said set wheel having an outer Wall with a plurality of detents formed in the inner surface of said wall, at least one pair of contacts having a first position and a second position mounted on said set wheel adjacent said cam member, a respective cam follower associated with each pair of contacts and connected to said set wheel, each of said cam followers engaging the periphery of said cam member and moving its associated pair of contacts from said first position to said second position upon engaging said camming means, said set wheel being rotatable relative to said cam member whereby the position during each revolution of the cam member at which the respec tive cam followers engage said camming means may be varied, and means including a detent spring engaging said detents to releasably hold said set wheel in a desired position.

References Cited UNITED STATES PATENTS 11/1951 Powell et al 2003 8 5/1965 Pittman 200-38 

6. IN A ROTARY SWITCH, THE COMBINATION WHICH COMPRISES, A ROTATABLE, CYLINDRICAL CAM MEMBER HAVING AN AXIAL CAMMING MEANS ON THE PERIPHERY THEREOF, A NANNULAR SET WHEEL POSITIONED ADJACENT THE CAM MEMBER IS SURROUNDING RELATIONSHIP, A PAIR OF CONTACTS HAVING A FIRST POSITION AND A SECOND POSITION MOUNTED ON THE SET WHEEL ADJACENT THE PERIPHERY OF THE CAM MEMBER, A CAM FOLLOWER CONNECTED TO SAID SET WHEEL AND POSITIONED IN ENGAGEMENT WITH THE PERIPHERY OF SAID CAM MEMBER AND FOR MOVING SAID CONTACTS FROM SAID FIRST POSITION TO SAID SECOND POSITION WHEN SAID CAMMING MEANS ENGAGES SAID CAM FOLLOWER, THE SET WHEEL BEING ROTATABLE RELATIVE TO THE CAM MEMBER TO 